diff options
Diffstat (limited to 'ANDROID_3.4.5/arch/x86/kernel/kprobes-opt.c')
| -rw-r--r-- | ANDROID_3.4.5/arch/x86/kernel/kprobes-opt.c | 512 |
1 files changed, 0 insertions, 512 deletions
diff --git a/ANDROID_3.4.5/arch/x86/kernel/kprobes-opt.c b/ANDROID_3.4.5/arch/x86/kernel/kprobes-opt.c deleted file mode 100644 index c5e410ee..00000000 --- a/ANDROID_3.4.5/arch/x86/kernel/kprobes-opt.c +++ /dev/null @@ -1,512 +0,0 @@ -/* - * Kernel Probes Jump Optimization (Optprobes) - * - * This program is free software; you can redistribute it and/or modify - * it under the terms of the GNU General Public License as published by - * the Free Software Foundation; either version 2 of the License, or - * (at your option) any later version. - * - * This program is distributed in the hope that it will be useful, - * but WITHOUT ANY WARRANTY; without even the implied warranty of - * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the - * GNU General Public License for more details. - * - * You should have received a copy of the GNU General Public License - * along with this program; if not, write to the Free Software - * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. - * - * Copyright (C) IBM Corporation, 2002, 2004 - * Copyright (C) Hitachi Ltd., 2012 - */ -#include <linux/kprobes.h> -#include <linux/ptrace.h> -#include <linux/string.h> -#include <linux/slab.h> -#include <linux/hardirq.h> -#include <linux/preempt.h> -#include <linux/module.h> -#include <linux/kdebug.h> -#include <linux/kallsyms.h> -#include <linux/ftrace.h> - -#include <asm/cacheflush.h> -#include <asm/desc.h> -#include <asm/pgtable.h> -#include <asm/uaccess.h> -#include <asm/alternative.h> -#include <asm/insn.h> -#include <asm/debugreg.h> - -#include "kprobes-common.h" - -unsigned long __recover_optprobed_insn(kprobe_opcode_t *buf, unsigned long addr) -{ - struct optimized_kprobe *op; - struct kprobe *kp; - long offs; - int i; - - for (i = 0; i < RELATIVEJUMP_SIZE; i++) { - kp = get_kprobe((void *)addr - i); - /* This function only handles jump-optimized kprobe */ - if (kp && kprobe_optimized(kp)) { - op = container_of(kp, struct optimized_kprobe, kp); - /* If op->list is not empty, op is under optimizing */ - if (list_empty(&op->list)) - goto found; - } - } - - return addr; -found: - /* - * If the kprobe can be optimized, original bytes which can be - * overwritten by jump destination address. In this case, original - * bytes must be recovered from op->optinsn.copied_insn buffer. - */ - memcpy(buf, (void *)addr, MAX_INSN_SIZE * sizeof(kprobe_opcode_t)); - if (addr == (unsigned long)kp->addr) { - buf[0] = kp->opcode; - memcpy(buf + 1, op->optinsn.copied_insn, RELATIVE_ADDR_SIZE); - } else { - offs = addr - (unsigned long)kp->addr - 1; - memcpy(buf, op->optinsn.copied_insn + offs, RELATIVE_ADDR_SIZE - offs); - } - - return (unsigned long)buf; -} - -/* Insert a move instruction which sets a pointer to eax/rdi (1st arg). */ -static void __kprobes synthesize_set_arg1(kprobe_opcode_t *addr, unsigned long val) -{ -#ifdef CONFIG_X86_64 - *addr++ = 0x48; - *addr++ = 0xbf; -#else - *addr++ = 0xb8; -#endif - *(unsigned long *)addr = val; -} - -static void __used __kprobes kprobes_optinsn_template_holder(void) -{ - asm volatile ( - ".global optprobe_template_entry\n" - "optprobe_template_entry:\n" -#ifdef CONFIG_X86_64 - /* We don't bother saving the ss register */ - " pushq %rsp\n" - " pushfq\n" - SAVE_REGS_STRING - " movq %rsp, %rsi\n" - ".global optprobe_template_val\n" - "optprobe_template_val:\n" - ASM_NOP5 - ASM_NOP5 - ".global optprobe_template_call\n" - "optprobe_template_call:\n" - ASM_NOP5 - /* Move flags to rsp */ - " movq 144(%rsp), %rdx\n" - " movq %rdx, 152(%rsp)\n" - RESTORE_REGS_STRING - /* Skip flags entry */ - " addq $8, %rsp\n" - " popfq\n" -#else /* CONFIG_X86_32 */ - " pushf\n" - SAVE_REGS_STRING - " movl %esp, %edx\n" - ".global optprobe_template_val\n" - "optprobe_template_val:\n" - ASM_NOP5 - ".global optprobe_template_call\n" - "optprobe_template_call:\n" - ASM_NOP5 - RESTORE_REGS_STRING - " addl $4, %esp\n" /* skip cs */ - " popf\n" -#endif - ".global optprobe_template_end\n" - "optprobe_template_end:\n"); -} - -#define TMPL_MOVE_IDX \ - ((long)&optprobe_template_val - (long)&optprobe_template_entry) -#define TMPL_CALL_IDX \ - ((long)&optprobe_template_call - (long)&optprobe_template_entry) -#define TMPL_END_IDX \ - ((long)&optprobe_template_end - (long)&optprobe_template_entry) - -#define INT3_SIZE sizeof(kprobe_opcode_t) - -/* Optimized kprobe call back function: called from optinsn */ -static void __kprobes optimized_callback(struct optimized_kprobe *op, struct pt_regs *regs) -{ - struct kprobe_ctlblk *kcb = get_kprobe_ctlblk(); - unsigned long flags; - - /* This is possible if op is under delayed unoptimizing */ - if (kprobe_disabled(&op->kp)) - return; - - local_irq_save(flags); - if (kprobe_running()) { - kprobes_inc_nmissed_count(&op->kp); - } else { - /* Save skipped registers */ -#ifdef CONFIG_X86_64 - regs->cs = __KERNEL_CS; -#else - regs->cs = __KERNEL_CS | get_kernel_rpl(); - regs->gs = 0; -#endif - regs->ip = (unsigned long)op->kp.addr + INT3_SIZE; - regs->orig_ax = ~0UL; - - __this_cpu_write(current_kprobe, &op->kp); - kcb->kprobe_status = KPROBE_HIT_ACTIVE; - opt_pre_handler(&op->kp, regs); - __this_cpu_write(current_kprobe, NULL); - } - local_irq_restore(flags); -} - -static int __kprobes copy_optimized_instructions(u8 *dest, u8 *src) -{ - int len = 0, ret; - - while (len < RELATIVEJUMP_SIZE) { - ret = __copy_instruction(dest + len, src + len); - if (!ret || !can_boost(dest + len)) - return -EINVAL; - len += ret; - } - /* Check whether the address range is reserved */ - if (ftrace_text_reserved(src, src + len - 1) || - alternatives_text_reserved(src, src + len - 1) || - jump_label_text_reserved(src, src + len - 1)) - return -EBUSY; - - return len; -} - -/* Check whether insn is indirect jump */ -static int __kprobes insn_is_indirect_jump(struct insn *insn) -{ - return ((insn->opcode.bytes[0] == 0xff && - (X86_MODRM_REG(insn->modrm.value) & 6) == 4) || /* Jump */ - insn->opcode.bytes[0] == 0xea); /* Segment based jump */ -} - -/* Check whether insn jumps into specified address range */ -static int insn_jump_into_range(struct insn *insn, unsigned long start, int len) -{ - unsigned long target = 0; - - switch (insn->opcode.bytes[0]) { - case 0xe0: /* loopne */ - case 0xe1: /* loope */ - case 0xe2: /* loop */ - case 0xe3: /* jcxz */ - case 0xe9: /* near relative jump */ - case 0xeb: /* short relative jump */ - break; - case 0x0f: - if ((insn->opcode.bytes[1] & 0xf0) == 0x80) /* jcc near */ - break; - return 0; - default: - if ((insn->opcode.bytes[0] & 0xf0) == 0x70) /* jcc short */ - break; - return 0; - } - target = (unsigned long)insn->next_byte + insn->immediate.value; - - return (start <= target && target <= start + len); -} - -/* Decode whole function to ensure any instructions don't jump into target */ -static int __kprobes can_optimize(unsigned long paddr) -{ - unsigned long addr, size = 0, offset = 0; - struct insn insn; - kprobe_opcode_t buf[MAX_INSN_SIZE]; - - /* Lookup symbol including addr */ - if (!kallsyms_lookup_size_offset(paddr, &size, &offset)) - return 0; - - /* - * Do not optimize in the entry code due to the unstable - * stack handling. - */ - if ((paddr >= (unsigned long)__entry_text_start) && - (paddr < (unsigned long)__entry_text_end)) - return 0; - - /* Check there is enough space for a relative jump. */ - if (size - offset < RELATIVEJUMP_SIZE) - return 0; - - /* Decode instructions */ - addr = paddr - offset; - while (addr < paddr - offset + size) { /* Decode until function end */ - if (search_exception_tables(addr)) - /* - * Since some fixup code will jumps into this function, - * we can't optimize kprobe in this function. - */ - return 0; - kernel_insn_init(&insn, (void *)recover_probed_instruction(buf, addr)); - insn_get_length(&insn); - /* Another subsystem puts a breakpoint */ - if (insn.opcode.bytes[0] == BREAKPOINT_INSTRUCTION) - return 0; - /* Recover address */ - insn.kaddr = (void *)addr; - insn.next_byte = (void *)(addr + insn.length); - /* Check any instructions don't jump into target */ - if (insn_is_indirect_jump(&insn) || - insn_jump_into_range(&insn, paddr + INT3_SIZE, - RELATIVE_ADDR_SIZE)) - return 0; - addr += insn.length; - } - - return 1; -} - -/* Check optimized_kprobe can actually be optimized. */ -int __kprobes arch_check_optimized_kprobe(struct optimized_kprobe *op) -{ - int i; - struct kprobe *p; - - for (i = 1; i < op->optinsn.size; i++) { - p = get_kprobe(op->kp.addr + i); - if (p && !kprobe_disabled(p)) - return -EEXIST; - } - - return 0; -} - -/* Check the addr is within the optimized instructions. */ -int __kprobes -arch_within_optimized_kprobe(struct optimized_kprobe *op, unsigned long addr) -{ - return ((unsigned long)op->kp.addr <= addr && - (unsigned long)op->kp.addr + op->optinsn.size > addr); -} - -/* Free optimized instruction slot */ -static __kprobes -void __arch_remove_optimized_kprobe(struct optimized_kprobe *op, int dirty) -{ - if (op->optinsn.insn) { - free_optinsn_slot(op->optinsn.insn, dirty); - op->optinsn.insn = NULL; - op->optinsn.size = 0; - } -} - -void __kprobes arch_remove_optimized_kprobe(struct optimized_kprobe *op) -{ - __arch_remove_optimized_kprobe(op, 1); -} - -/* - * Copy replacing target instructions - * Target instructions MUST be relocatable (checked inside) - * This is called when new aggr(opt)probe is allocated or reused. - */ -int __kprobes arch_prepare_optimized_kprobe(struct optimized_kprobe *op) -{ - u8 *buf; - int ret; - long rel; - - if (!can_optimize((unsigned long)op->kp.addr)) - return -EILSEQ; - - op->optinsn.insn = get_optinsn_slot(); - if (!op->optinsn.insn) - return -ENOMEM; - - /* - * Verify if the address gap is in 2GB range, because this uses - * a relative jump. - */ - rel = (long)op->optinsn.insn - (long)op->kp.addr + RELATIVEJUMP_SIZE; - if (abs(rel) > 0x7fffffff) - return -ERANGE; - - buf = (u8 *)op->optinsn.insn; - - /* Copy instructions into the out-of-line buffer */ - ret = copy_optimized_instructions(buf + TMPL_END_IDX, op->kp.addr); - if (ret < 0) { - __arch_remove_optimized_kprobe(op, 0); - return ret; - } - op->optinsn.size = ret; - - /* Copy arch-dep-instance from template */ - memcpy(buf, &optprobe_template_entry, TMPL_END_IDX); - - /* Set probe information */ - synthesize_set_arg1(buf + TMPL_MOVE_IDX, (unsigned long)op); - - /* Set probe function call */ - synthesize_relcall(buf + TMPL_CALL_IDX, optimized_callback); - - /* Set returning jmp instruction at the tail of out-of-line buffer */ - synthesize_reljump(buf + TMPL_END_IDX + op->optinsn.size, - (u8 *)op->kp.addr + op->optinsn.size); - - flush_icache_range((unsigned long) buf, - (unsigned long) buf + TMPL_END_IDX + - op->optinsn.size + RELATIVEJUMP_SIZE); - return 0; -} - -#define MAX_OPTIMIZE_PROBES 256 -static struct text_poke_param *jump_poke_params; -static struct jump_poke_buffer { - u8 buf[RELATIVEJUMP_SIZE]; -} *jump_poke_bufs; - -static void __kprobes setup_optimize_kprobe(struct text_poke_param *tprm, - u8 *insn_buf, - struct optimized_kprobe *op) -{ - s32 rel = (s32)((long)op->optinsn.insn - - ((long)op->kp.addr + RELATIVEJUMP_SIZE)); - - /* Backup instructions which will be replaced by jump address */ - memcpy(op->optinsn.copied_insn, op->kp.addr + INT3_SIZE, - RELATIVE_ADDR_SIZE); - - insn_buf[0] = RELATIVEJUMP_OPCODE; - *(s32 *)(&insn_buf[1]) = rel; - - tprm->addr = op->kp.addr; - tprm->opcode = insn_buf; - tprm->len = RELATIVEJUMP_SIZE; -} - -/* - * Replace breakpoints (int3) with relative jumps. - * Caller must call with locking kprobe_mutex and text_mutex. - */ -void __kprobes arch_optimize_kprobes(struct list_head *oplist) -{ - struct optimized_kprobe *op, *tmp; - int c = 0; - - list_for_each_entry_safe(op, tmp, oplist, list) { - WARN_ON(kprobe_disabled(&op->kp)); - /* Setup param */ - setup_optimize_kprobe(&jump_poke_params[c], - jump_poke_bufs[c].buf, op); - list_del_init(&op->list); - if (++c >= MAX_OPTIMIZE_PROBES) - break; - } - - /* - * text_poke_smp doesn't support NMI/MCE code modifying. - * However, since kprobes itself also doesn't support NMI/MCE - * code probing, it's not a problem. - */ - text_poke_smp_batch(jump_poke_params, c); -} - -static void __kprobes setup_unoptimize_kprobe(struct text_poke_param *tprm, - u8 *insn_buf, - struct optimized_kprobe *op) -{ - /* Set int3 to first byte for kprobes */ - insn_buf[0] = BREAKPOINT_INSTRUCTION; - memcpy(insn_buf + 1, op->optinsn.copied_insn, RELATIVE_ADDR_SIZE); - - tprm->addr = op->kp.addr; - tprm->opcode = insn_buf; - tprm->len = RELATIVEJUMP_SIZE; -} - -/* - * Recover original instructions and breakpoints from relative jumps. - * Caller must call with locking kprobe_mutex. - */ -extern void arch_unoptimize_kprobes(struct list_head *oplist, - struct list_head *done_list) -{ - struct optimized_kprobe *op, *tmp; - int c = 0; - - list_for_each_entry_safe(op, tmp, oplist, list) { - /* Setup param */ - setup_unoptimize_kprobe(&jump_poke_params[c], - jump_poke_bufs[c].buf, op); - list_move(&op->list, done_list); - if (++c >= MAX_OPTIMIZE_PROBES) - break; - } - - /* - * text_poke_smp doesn't support NMI/MCE code modifying. - * However, since kprobes itself also doesn't support NMI/MCE - * code probing, it's not a problem. - */ - text_poke_smp_batch(jump_poke_params, c); -} - -/* Replace a relative jump with a breakpoint (int3). */ -void __kprobes arch_unoptimize_kprobe(struct optimized_kprobe *op) -{ - u8 buf[RELATIVEJUMP_SIZE]; - - /* Set int3 to first byte for kprobes */ - buf[0] = BREAKPOINT_INSTRUCTION; - memcpy(buf + 1, op->optinsn.copied_insn, RELATIVE_ADDR_SIZE); - text_poke_smp(op->kp.addr, buf, RELATIVEJUMP_SIZE); -} - -int __kprobes -setup_detour_execution(struct kprobe *p, struct pt_regs *regs, int reenter) -{ - struct optimized_kprobe *op; - - if (p->flags & KPROBE_FLAG_OPTIMIZED) { - /* This kprobe is really able to run optimized path. */ - op = container_of(p, struct optimized_kprobe, kp); - /* Detour through copied instructions */ - regs->ip = (unsigned long)op->optinsn.insn + TMPL_END_IDX; - if (!reenter) - reset_current_kprobe(); - preempt_enable_no_resched(); - return 1; - } - return 0; -} - -int __kprobes arch_init_optprobes(void) -{ - /* Allocate code buffer and parameter array */ - jump_poke_bufs = kmalloc(sizeof(struct jump_poke_buffer) * - MAX_OPTIMIZE_PROBES, GFP_KERNEL); - if (!jump_poke_bufs) - return -ENOMEM; - - jump_poke_params = kmalloc(sizeof(struct text_poke_param) * - MAX_OPTIMIZE_PROBES, GFP_KERNEL); - if (!jump_poke_params) { - kfree(jump_poke_bufs); - jump_poke_bufs = NULL; - return -ENOMEM; - } - - return 0; -} |